Let A and B be two non-empty bounded sets, and A and B are disjoint. Is...
Let A, B be non-empty, bounded subsets of R. a) If the statement is true, prove it. If the statement is false, give a counterexample: sup(AUB) = max(sup(A), sup(B)}. b) If the statement is true, prove it. If the statement is false, give a counterexample: If An B + Ø, then sup(A n B) = min{sup(A), sup(B)}. E 选择文件
Let A be a non-empty subset of R that is bounded above. (a) Let U = {x ∈ R : x is an upper bound for A}, the set of all upper bounds for A. Prove that there exists a u ∈ R such that U = [u, ∞). (b) Prove that for all ε > 0 there exists an x ∈ A such that u − ε < x ≤ u. This u is one shown to exist in...
1. Let A, B be two non-empty sets and f: A + B a function. We say that f satisfies the o-property if VC+0.Vg, h: C + A, fog=foh=g=h. Prove that f is injective if and only if f satisfies the o-property.
5. Let S be a non empty bounded subset of R. If a > 0, show that sup (as) = a sup S where as = {as : ES}. Let c = sup S, show ac = sup (aS). This is done by showing (a) ac is an upper bound of aS. (b) If y is another upper bound of as then ac S7 Both are done using definitions and the fact that c=sup S.
(6) Let S c R be non-empty and bounded above. Let q = sup S. Show that q E bd S. (6) Let S c R be non-empty and bounded above. Let q = sup S. Show that q E bd S.
Let A be a non empty subset of R that is bounded below and let a=inf A. If a a&A, prove thal x is a limit point of A
4. Let A, B CR be non-empty open sets. Prove that AU B is an open set.
#9-11 please 9. Let A and B be disjoint sets in the universe U. Let C be a proper subset of A. (a) Draw a Venn Diagram representing this information. (b) What is BAC? 10. Let A be a set in the universe U. (a) Draw a Venn Diagram and shade in the region A. Then draw another Venn Diagram with the same set A, but shade in A'. (b) What is A'U A? 11. Give an example of three...
No Contradiction 2. Let A and B be non-empty subsets of R, and suppose that ACB. Prove that if B is bounded below then inf B <inf A.
5. Let S be a non-empty bounded subset of R. If a > 0, show that sup (aS) = a sup S where aS = {as : s E S}. Let c = sup S, show ac = sup (aS). This is done by showing: (a) ac is an upper bound of aS. (b) If y is another upper bound of aS then ac < 7. Both are done using definitions and the fact that c=sup S.